It describes “a look shared by two people with each wishing that the other will initiate something that both desire but which neither one wants to start. This could perhaps be translated more succinctly as ‘eye-contact implying “after you…”‘.”
You know the feeling.
Also appealingly untranslatable: the Russian word пошлость, roughly pronounced “posh-lost“. Wikipedia claims that it “roughly means a mixture of banality, commonality and vulgarity” – or, the quality inherent in Big Brother.